Crystal River current., 1887-02-19
THE sEvxaM TUNNEL.

e This remarkable tunnel, which, with
IL connecting links and necessary do
tails has cost the Great Western Rail-
way company about 1900. 900 ster-
ling, and has been in construction be-
tween thirteen and fourteen years. has
been opened for goods traffic. The
passenger traffic will be delayed .
couple Of months, owing to the heavy
work on portion Of the connecting
lines on the Gloucestershire side Of the
Severn. The tunnel. which was origi-
nally designed by Mr.. Charles Richard
son, C. E. afterwards associated
with Sir John Hawkshaw as chief IN
stead Of consulting engineer). was
commenced by the Great Western Rail
way company in March. 1873. they
having obtained three, acts offf5krlia-
ment in 1872. II was vt first intended
td ne.44 miles in length. butthis lensth
was afterward reduced bg iG chaiiis.
anrl. OF this distance Fl miles are below
the rapidly flowing estuary of the Sew
ern, at point half a mile below the new
passage where the passengers now cross
from the Bristol and South Wales Union
railway, on the Worcestershire side OF
the river, to Portskwet on the Mon
mouth side. From the point at which
the tunnel line leaves the Bristol and
South Wales Union line between Patch
way and Pilning to Rogiett, the juno
tion station where it joins the South
Waleshection, the distance altogether
is z malSs furlongs, including the
deep cFtings to the tunnel entrances
on eitTer side. The Great Western
Railway company carried on the
work themselves till 1879, and
drove the preliminary heading from
either side of the river to within 120
yfds, when they tapped handspring
on the Monmouthshire side. and in less
than 4 Nay the whole workings were
flooded. II, was then that Sir John
Hawkshaw WAS appointed chief engi-
neer, in conjunction with Mr.. Richard
son, and Mr.. T. A. Walker undertook
the. contract, under the most discourage
ing circumstances; and the works were
not clear of water till November, 1880.
The 1unction Of the headings was made
in ,September, 1881; the level of the
rails having BEEN lowered. at the sug-
gestion Of Sin John Hawkshaw. Is feet
in order to gst more thickness under
the riyer-bed. That this was absolute
II necessary Wis clear from the fact
that hole 1Qeteety long was found in
the mari Of tts river-bed at . depres-
sion known 40 the Salmon pool; and
the river. eemlRe Through ,this, flooded
the work Oh the Gloucestershire side.
This difficulty was surmounted BY fill
ing fn tie place with .ciay-puddle and
cIay-puddle bags, and the works were
then pumped out. In October. 1888.
the old spring on the Monmouthshire
sids was again tapped, and in such
volume that the water rushed in at the
vrate Of 81, 600 gallons per minute. and
rising at the rate of four feet per hour,
it flooded considerable section Of the
completed work. Divers had to be
employed to descend the flooded works
and shut and iron door 500 feet from
the bottom Of the shaft. and again were
the works pumped dry, by the aid OF
more powerful pumps. During this
process tidal wave breaking in over
sthe marsh between Sunbrook and
Caldecott, on the Monmouthshire side.
descended the shaft, and flooded an-
other section Of the tunnel works
inland, but this was easily dealt
with. Thus battling with unexamplcd
difficulties the engineers have til
umphed over disasters which constantly
threatened to swamp the whole scheme
and render all the work futile. During
the past twelve months great attention
has been paid to the increase Of the
pumping power. and duplicate sets Of
pumps which have now been erected
are capable of discharging at the rate
Of 26. 600 600 gallons Of water per day.
A new shaft 1s0 feet deep has been sunk
ON the ,MonmoutAal al1ge side for six Of
these pumps, arm t6efe are in all eight
34-inch pumps, one S7-inch. one So
inch, two 30-inch, and two 28-inch
pumps. The tunnel is 26 feet wide and
20 feet high, and has been excavated
through hard Pennaul sandstone. and
coal measures, the conglomerate over
lying the coal measures. and shale. red
mari, and new red sandstone. In the
mid-channel Of the river there is a de-
u